I'm looking for some advice... I've been playing with Oscommerce and have been fairly happy with it, except for the URL structure. I know there a dozen or so contributions that claim to deliver SEO-friendly URLs. Since adding contributions is a bit of a pain in OSC (they should take a lesson from WordPress) I'd like to get some suggestions on which ones work best before I kick the tires on all of them. Which one(s) do you like?